Abstract: To investigate the effectiveness of different activities in intentional vocabulary learning, a meta-analysis by CMA3.0 was conducted on 26 studies comparing elaborate processing activities and repetition processing activities. The results showed that compared to repetition processing activities, elaborate processing activities were more effective in vocabulary acquisition and retention, with immediate effect of 0.355 and delayed retention effect of 0.540. Subgroup analysis revealed that only retrieval practice and vocabulary use were more effective than repetition, while keyword method, semantic inferencing, and semantic association had no significant advantage. Vocabulary test format and learner’s second language proficiency level moderated the effectiveness of elaborate processing activities. Elaborate processing activities had significant effects on form tests rather than on meaning tests; and it was more beneficial for low-level learners compared to higher-level learners. Different cultural traditions also influenced the effectiveness of fine processing to certain extent, but the influence was not significant.